Armchair



FIG. 1 is a front-left side perspective view of an armchair showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a left side elevational view thereof, the right side being a mirror image; and,

FIG. 4 is a top plan view thereof. 

The ornamental design for an armchair, as shown and described. 